Illustrated history of the United States mint / with a complete description of American coinage, from the earliest period to the present time

by Unknown

The Assaying Rooms.

These are on the second floor, in the southwest corner of the building. In one of these are fires, stills, and other appliances used in the delicate and complicated process of assay, by which the specific standard of the fineness and purity of the various metals are established and declared.